Chemical lasers are well-known in which a chemically pumped lasing action is obtained directly from gaseous molecules that are vibrationally excited through a chemical reaction. Typically hydrogen or deuterium is used as the fuel which reacts with an oxidizing agent such as a fluorine-containing compound. The fluorine atom containing gaseous material is expanded through a nozzle to form a supersonic jet, and the hydrogen is then diffused into the expanded jet flow mixture to effect a chemical reaction in an optical cavity whose axis is transverse to the flow. Multiple nozzle designs have been used to provide more efficient mixing between the fluorine-containing gas and the hydrogen. Such a multiple nozzle grid is shown, for example, in U.S. Pat. No. 3,688,215.
In the past such nozzle arrays or grids have been either machined from a single block of metal or assembled from individually machined elements. Either approach has proved very costly and time consuming. The shape of the supersonic nozzles results in surface contours which are difficult to machine. The nozzles may be quite small. For example, nozzles have been arranged in grids with as many as 700 or 800 nozzles per square inch. Nozzles may be either two-dimensional or three-dimensional types. They may change in cross-sectional shape over the length of the nozzle, as changing from a circular cross-section at the throat to a hexagonal cross-section at the mouth of the nozzle. The manufacture of such nozzles in compact arrays has been difficult to achieve.